Investigation of chatter suppression in slender endmill via a frictional damper

The main purpose of this paper is to propose a frictional damper so as to enhance structural damping leading to the chatter suppression in the slender endmill tool. The proposed damper is composed of a core press fitted inside a multi-fingered hollow cylinder. Core and cylinder both are press fitted into an axial hole inside the tool. First, an analytical model is developed for the damper. Then, a parameter study is conducted to find optimum parameters of the damper for the increase of the stability limit as much as possible. In order to validate the analytical model, a nonlinear finite element model of the damped milling tool is simulated using ANSYS software package. Having finite element model, the stability lobe diagrams for simple tool and optimally damped tool are extracted from frequency response functions. Modal test is applied to a real specimen of damped tool in order to validate finite element results. Good agreement between experiments and modeling is obtained.